Reciprocating piston compressor



March 24, 1931. c, SCHAER 1,797,245

' RECIPROGAI-ING PISTON COMPRESSOR Filed Sept. 29, L928 ,A EJ NBK I Patented Mar. 24, 1931 ,r-m m fs'rprrssj PATENT m 1 i CHARLES serum, or LAnenN'rnAL, swrrznRLAnnnssIGNon' TO rnnrrnivr :5

: SULZERV rnnnnssoornrn nNoNYMnor wmrnnrnun, SWITZERLAND,

nnor rnocarrn errsron oorirrnnsson 7 a plication fil ed September 29,1925, gain No. 309,265, and in Switzerland October '3, 1927.

This I invention relates to high pressure 2 to a crossheadficonnected by a piston rod reciprocating compressors of the kind in 4 to the single-acting piston 5 which recipwhich power is transmitted fromthe piston of the driving engine to'the compressor piston through an oscillating column of liquid. According to this invention means are provided for varying thevolume of the oscillating column of liquid so as to enableithe work performed by the compressor to be Va ried independently of the working of the driving engine. This variation in the volume of the liquid column can be obtained by.

a valve or'other controllingrmeans operated by hand,'connected :tothe driving gear of the? engine or operating automatically By means of such a control and without changing-the length ofthe stroke offthe interme-.

diate pistonorcompressor pistony the setting of these pistons within their respective cylinders can be varied, e; g. the piston can be movedso as tozhave aqhigher or lower position its cylinder in the case of, verticallyarranged compressors. 1

Various constructionsaccording to this-invention are diagrammatically illustrated by way of example in the accompanying drawings, in which I Figure 1 shows a general arrangement of a-fsingle-stage piston compressor according torthis'inventlon m'vert1cal sectlon,

1 F Igure- 2. 1s a simllar view-of a mod1fie,d

' arrangement showing the controllin'g mechanisrn',

v Figure 3 is a vertical section of a further modification also according to this 'lHVBIltion; v

-I Figure 4'is "a vertical sectioni'through. a three-stage compressor and its driving machine 1 in which the intermediate pistons are actuated by: a moving column of liquid 'and- Figure 5 is'a cross-sectiononthe'line a=-a of Figured; i v The apparatus comprises essentially adriv? ing machine actuating a piston byr'means 5 of which a column oi liquid-is displaced,, the

column-of liquid in turn operating a driving or intermediate piston by which the; com-- pressor pistons are actually reciprocated. r In the constructionsillustrated the crank 1 of the driving engine I) is connected bygaf rod roeates in the cylinder 61 Thecylinder contalns a column of liquid 7 actingupon the driving or intermediatepiston 8 to which is connected by means of a coupling 9 a comwith the working conditions. In the particular e'xainple illustrated the device compr'ise's a cock provided witha hand actuated lever by means of which the column of 'liquid can be connected at willto a discharge pipe 14: if the volume of liquid is to be -reduced."

lVhen this-volume-isf to berestoredpaddi-l tiona'l liquid is introducedinto thecyli'nder through {a supply pipe- 15, this additional liquid being forced in by any suitable pump or the like (notrshown; in}. the drawings) preferably duringrthe suction-stroke of-thel' compressor piston, p I I In the modified arrangement illustrated in Figure 2, ports 41,42, 43 are provided in the wall of the" cylinder" controlled by a piston or like valve 44. The intermediate piston is shown'in its uppermost position with the compressor piston (not-illustrated) at l the end of its instroke andwiththeYsma llest;

clearance between itsupper endand its'cylin der cover. Whenthe control piston 44 is brought into the position b shown in dotted lines; i. e. when the piston-is'moved longitudinallyby actuatingfthe hand wheel 45 on the screwthreaded shaft d6, the liquid col umn will be placed in ';communication through a conduit, 61 with the outlet pipe as soon-as the piston-8uncovers the port 43. Asa result during the delivery or pressure stroke the intermediate or driving piston 8 will not rise above the line; 0 that is to say the'fclearance in the compressor cylinderwill have been materially'increased. In Figure'3a modified construction lustrated for. varying a the volume of the liquid'column comprisingiessentially @LCQIL:

trol member 17 in the form of a piston mounted to slide within a cylinder 16. The piston 17 is connected by a rod18 pivoted at 19 to a link 20 one end of which is connected to the coupling 9 of the compressor piston 10,

whilst, the other end is pivotally connected by a link 22 to a lever 24 having its fulcrum at 23. The operating handle 25 of the lever 24 can be locked in any desired position over atoothed quadrant or the like 26.

The piston 17 controls a conduit 27 and particular that illustrated in Figure 3, is as follows It the control piston 17 is in the position shown by full lines in Figure 3, there will be the minimum clearance within the compression 'cylinder. Whilst the intermediate piston 8 has anoperating stroke 8 the corresponding. stroke of the compressorpiston 10 will be that indicated at .9 i. e the .con:

trol member is so set that when the lower face of the piston 8 is on the line 50, and the pivot 19 at thepoint 51, the-conduit 27 will be open 'so'that liquid can escape from the cylinder6 into the discharge pipe 28. 'Thus the stroke of the piston 8 is definitely ter- 7 minated.

If the clearance in the compressor cylin der is to be increased the lever 24 is moved.

into the position shown in dotted lines .so that the control piston 17 will enable the liquid column to establish communication with the discharge pipe 28 at an earlier point in the stroke than in the position shown in 'full lines. As a-result the lower face ofthe intermediate piston 8 will have different terminal positions, i. e. the stroke will be that indicated at 8 with the result that the compressor piston will also have afmodified' stroke, i. e. that indicated by-the lines a As aresult the clearance in-the compression cylinder will be increased to the distance indicated at 8. I

, *To compensate for the loss of liquid due to the reduced volume of the liquid column the pump 29 during the return stroke; of the piston 5; forces through the conduit 27 at least the same quantity as that discharged so that during the compression stroke of'the. compressor piston 10 the liquid column is supplemented. to its normal length or volume.

When' the lever 24 is moved to the position shown dotted. lines the'clearance will be smaller than 5 as the control piston will open the conduit 27 still later, the position 51 of the pivot 19 determining the moment when the conduit 27 opens being the same whatever the setting of the piston 17 Figure. 4 illustrates a compressor having "threestages L II, III and the piston or the driving machine comprises a double-acting piston 33 and a single-act ng p ston34. One

race of the double-acting piston33 actson a liquid column '35 which actuates the intermediate piston 36of the second stage, whilst the other face of the piston 33 acts on a liquid column 37 which operates the driving piston 38 of the third stage; The piston 34 operates the liquid column 40 which actuates the-intermediate piston 39 of the first stage.

According to this inventionone or more of the stages can be furnished with means for varying. the volume of the oscillating column of liquid, one such device which is generally similar tothat already described with relation to Figure 3, being shown in Figure 5 as connected to the compressor piston of the third stage.

In this arrangement the setting of the control piston 17 for varying the volume of the liquid column 37 is effected by means of av hand wheel on a spindlefurnished with a' screwthreaded portion 46 supported in. a nut 47: for adjusting the position of a pivot 21 at one end of the link 20 to'which the rod 18. ofthe piston 17 is pivoted at '19. The moment at which the discharge conduit27 is opened and therefore the central position of the compressor piston, is controlled by the setting of the valve '17 through the variable control device 45. Additional liquid is supplied to the liquid column through a pipe 30.

I claim:

1. In a reciprocating compressorplant, th combination with a driving engine of a reciprocating compressor, a liquid column for transmitting power trom the pistonv of the driving engine to the compressor piston, and meansfor varying the volume of the liquid column for the purpose of altering the stroke in its height and thus varying the work performed by the compressor.

2. In a reciprocating compressor plant, the

' combination with a driving engine of a reciprocating compressor, a liquid column for transmitting powerfrom the piston of the driving engine to the compressor-piston, and manually controlled means for varying the volume of the liquid column for the purpose of altering the stroke in its height and thus varying the work pressor.

3 'In a reciprocating compressor plant, the combination with a driving engine of a reciprocating compressor, a hquid column .for

performed by the comtransmitting power from the piston of the 7 driving engine to the compressorpiston, and mechanically driven means for varying the [volume of the liquid column for the purpose of altering the stroke in its height and thus varying the work performed by the compressor. p r

4. In a reciprocating compressor plant, the combination with a driving engine of a reciprocating. compressor, a liquid column for transmitting power from the piston of the driving engine to the compressor piston and means including an automatically operating device for varying the volume of the liquid column for the purpose of altering the stroke in its height and thus varying the. work performedby the compressor.

5. In a reciprocating multi-stage compressor plant, the combination with a driving engine of a plurality of reciprocating compressors, liquid columns for transmitting power from the piston of the drivingengine to the compressor pistons, and means for varying the volume of the several liquid columns for signature.

the purpose of altering the stroke in its height and thus varying the work performed by the compressors. 7

- In testimony whereof I have affixed my CHARLES SCI-IAER. r 

